Chloe: Jonny was here boxes hooter phenergan use smash clumsy X-ray analysis revealed microscopic gold threads up to about 8 microns wide–ten times thinner than an average human hair–in the cells of the eucalyptus trees. The highest concentrations of gold are found in the leaves because, researchers say, large amounts of the metal are toxic to the trees so they rid themselves of the mineral by transporting the particles to their extremities.